The Wyoming State Geological Survey (WSGS) published a new pamphlet about the geology in Guernsey State Park in eastern Wyoming. It is the third in a series of information pamphlets highlighting the geology in Wyoming’s state parks.

“We are pleased for this opportunity to provide information to the public illuminating the geology of Wyoming’s state parks. With these pamphlets, we hope to help answer some of the questions that might arise when visitors travel to these site,” says WSGS geologist Kelsey Kehoe.

Guernsey State Park, home to Guernsey Reservoir, is situated along the North Platte River just north of the town of Guernsey. One of the most prominent features of the park are the bluffs of limestone and sandstone that rise above the eastern half of the reservoir and along the river. The pamphlet explains the origin of these rocks and others that occur around the reservoir.

The park is located within the Hartville Uplift, a small mountain range with rocks showcasing more than 2.5 billion years of Earth’s history. This region has a rich mining history dating back to approximately 13,000 to 11,500 years ago, making it one of the oldest mining sites in North America. For millennia, Native Americans mined hard siliceous chert and hematite, also known as red ochre, in the Hartville Uplift area for a variety of uses.

The goal of the publication series is to provide park visitors with a glimpse of the area’s geology. Pamphlets are available for Curt Gowdy and Seminoe state parks, both in the southern portion of the state. Pamphlets now in production focus on Glendo, Buffalo Bill, Keyhole, and Bear River state parks.

Pamphlets are free and are available at the parks’ visitor centers, at the WSGS office on the University of Wyoming campus in Laramie, and as free downloads from the WSGS' website.